We propose and demonstrate a novel optical orthogonal frequency-division multiple access (OFDMA)-based metro-access integrated network with dynamic resource allocation. It consists of a single fiber OFDMA ring and many single fiber OFDMA trees, which transparently integrates metropolitan area networks with optical access networks. The single fiber OFDMA ring connects the core network and the ce...

OFDMA is a new modulation method for the 2 generation of Broadband Wireless Access (BWA) systems that combines both upstream access and modulation together. OFDMA is based on modulating multiple orthogonal sub-carriers. Unlike traditional multi-carrier modulation schemes, several transmitters of the multiple access system modulate the sub-carriers simultaneously. OFDMA offers up to an 18dB gain...

The mobile Worldwide Interoperability for Microwave Access (Mobile WiMAX) air interface adopts orthogonal frequency division multiple access (OFDMA) as multiple access technique for its uplink (UL) and downlink (DL) to improve the multipath performance. All OFDMA based networks including mobile WiMAX experience the problem of high peak-toaverage power ratio (PAPR). The literature is replete wit...

For wireless local area networks based on OFDM we study the sum rate of time and frequency division multiple access (TDMA, OFDMA) as well as superimposed transmission (SUP). In the analysis traffic-imposed constraints on the maximum exploitable user rates apply. For a large number of subcarriers the effective sum rate is low with TDMA but much higher with OFDMA and SUP. The spatial properties o...

In this paper, two candidates for a next generation (4G) downlink system in a multi−cell environment are studied in respect to their error performance. We investigate on the one hand, an orthogonal frequency division multiplexing (OFDM) based multiple access scheme (OFDMA), and on the other hand, a multi−carrier code division multiple access (MC−CDMA) scheme. The studies of both transmission sc...

In this paper, a novel sub-channel based uplink Orthogonal Frequency Domain Multiple Access (OFDMA) random access scheme is proposed. In the next generation Wireless Local Area Network (WLAN), OFDMA was adopted in order to enhance throughput performance. OFDMA can be used for both downlink and uplink. In order to utilize OFDMA for uplink, AP needs to schedule stations’ packet transmission. In o...

The transfer of data from multiple internet things (IoT) devices requires the use a robust and efficient access (MA) solution. This paper considers orthogonal frequency division MA (OFDMA) technique for light-fidelity (LiFi)-based IoT uplink using infrared to transmit mobile users fixed point. conventional schemes based on allocate distinct subcarriers each user sharing same time slot. We consi...

11:45 – 13:15 S1 OFDMA Systems I 1 Rate Adaptive Resource Allocation with Fairness Control for OFDMA Networks Emanuel B. Rodrigues (Universitat Politècnica de Catalunya, Spain); Ferran Casadevall (Universitat Politècnica de Catalunya, Spain) 2 Downlink Rate-Guaranteed Scheduling for Multiuser OFDMA Cellular Systems Jerzy Martyna (Jagiellonian University, Faculty of Mathematics and Computer Scie...

OFDMA is considered as one of the major candidates for broadband wireless access. The OFDMA signal is usually coherently demodulated, requiring the channel estimation which can be estimated using a known pilot signal. In multicell environment, the performance of channel estimation is mainly limited by intercell interference. It is desirable to use a pilot signal that can estimate the channel in...